2 * drivers/usb/core/usb.c
4 * (C) Copyright Linus Torvalds 1999
5 * (C) Copyright Johannes Erdfelt 1999-2001
6 * (C) Copyright Andreas Gal 1999
7 * (C) Copyright Gregory P. Smith 1999
8 * (C) Copyright Deti Fliegl 1999 (new USB architecture)
9 * (C) Copyright Randy Dunlap 2000
10 * (C) Copyright David Brownell 2000-2004
11 * (C) Copyright Yggdrasil Computing, Inc. 2000
12 * (usb_device_id matching changes by Adam J. Richter)
13 * (C) Copyright Greg Kroah-Hartman 2002-2003
15 * NOTE! This is not actually a driver at all, rather this is
16 * just a collection of helper routines that implement the
17 * generic USB things that the real drivers can use..
19 * Think of this as a "USB library" rather than anything else.
20 * It should be considered a slave, with no callbacks. Callbacks
24 #include <linux/module.h>
25 #include <linux/moduleparam.h>
26 #include <linux/string.h>
27 #include <linux/bitops.h>
28 #include <linux/slab.h>
29 #include <linux/interrupt.h> /* for in_interrupt() */
30 #include <linux/kmod.h>
31 #include <linux/init.h>
32 #include <linux/spinlock.h>
33 #include <linux/errno.h>
34 #include <linux/usb.h>
35 #include <linux/usb/hcd.h>
36 #include <linux/mutex.h>
37 #include <linux/workqueue.h>
38 #include <linux/debugfs.h>
41 #include <linux/scatterlist.h>
43 #include <linux/dma-mapping.h>
48 const char *usbcore_name
= "usbcore";
50 static bool nousb
; /* Disable USB when built into kernel image */
52 #ifdef CONFIG_USB_SUSPEND
53 static int usb_autosuspend_delay
= 2; /* Default delay value,
55 module_param_named(autosuspend
, usb_autosuspend_delay
, int, 0644);
56 MODULE_PARM_DESC(autosuspend
, "default autosuspend delay");
59 #define usb_autosuspend_delay 0
64 * usb_find_alt_setting() - Given a configuration, find the alternate setting
65 * for the given interface.
66 * @config: the configuration to search (not necessarily the current config).
67 * @iface_num: interface number to search in
68 * @alt_num: alternate interface setting number to search for.
70 * Search the configuration's interface cache for the given alt setting.
72 struct usb_host_interface
*usb_find_alt_setting(
73 struct usb_host_config
*config
,
74 unsigned int iface_num
,
77 struct usb_interface_cache
*intf_cache
= NULL
;
80 for (i
= 0; i
< config
->desc
.bNumInterfaces
; i
++) {
81 if (config
->intf_cache
[i
]->altsetting
[0].desc
.bInterfaceNumber
83 intf_cache
= config
->intf_cache
[i
];
89 for (i
= 0; i
< intf_cache
->num_altsetting
; i
++)
90 if (intf_cache
->altsetting
[i
].desc
.bAlternateSetting
== alt_num
)
91 return &intf_cache
->altsetting
[i
];
93 printk(KERN_DEBUG
"Did not find alt setting %u for intf %u, "
94 "config %u\n", alt_num
, iface_num
,
95 config
->desc
.bConfigurationValue
);
98 EXPORT_SYMBOL_GPL(usb_find_alt_setting
);
101 * usb_ifnum_to_if - get the interface object with a given interface number
102 * @dev: the device whose current configuration is considered
103 * @ifnum: the desired interface
105 * This walks the device descriptor for the currently active configuration
106 * and returns a pointer to the interface with that particular interface
109 * Note that configuration descriptors are not required to assign interface
110 * numbers sequentially, so that it would be incorrect to assume that
111 * the first interface in that descriptor corresponds to interface zero.
112 * This routine helps device drivers avoid such mistakes.
113 * However, you should make sure that you do the right thing with any
114 * alternate settings available for this interfaces.
116 * Don't call this function unless you are bound to one of the interfaces
117 * on this device or you have locked the device!
119 struct usb_interface
*usb_ifnum_to_if(const struct usb_device
*dev
,
122 struct usb_host_config
*config
= dev
->actconfig
;
127 for (i
= 0; i
< config
->desc
.bNumInterfaces
; i
++)
128 if (config
->interface
[i
]->altsetting
[0]
129 .desc
.bInterfaceNumber
== ifnum
)
130 return config
->interface
[i
];
134 EXPORT_SYMBOL_GPL(usb_ifnum_to_if
);
137 * usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number.
138 * @intf: the interface containing the altsetting in question
139 * @altnum: the desired alternate setting number
141 * This searches the altsetting array of the specified interface for
142 * an entry with the correct bAlternateSetting value and returns a pointer
143 * to that entry, or null.
145 * Note that altsettings need not be stored sequentially by number, so
146 * it would be incorrect to assume that the first altsetting entry in
147 * the array corresponds to altsetting zero. This routine helps device
148 * drivers avoid such mistakes.
150 * Don't call this function unless you are bound to the intf interface
151 * or you have locked the device!
153 struct usb_host_interface
*usb_altnum_to_altsetting(
154 const struct usb_interface
*intf
,
159 for (i
= 0; i
< intf
->num_altsetting
; i
++) {
160 if (intf
->altsetting
[i
].desc
.bAlternateSetting
== altnum
)
161 return &intf
->altsetting
[i
];
165 EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting
);
167 struct find_interface_arg
{
169 struct device_driver
*drv
;
172 static int __find_interface(struct device
*dev
, void *data
)
174 struct find_interface_arg
*arg
= data
;
175 struct usb_interface
*intf
;
177 if (!is_usb_interface(dev
))
180 if (dev
->driver
!= arg
->drv
)
182 intf
= to_usb_interface(dev
);
183 return intf
->minor
== arg
->minor
;
187 * usb_find_interface - find usb_interface pointer for driver and device
188 * @drv: the driver whose current configuration is considered
189 * @minor: the minor number of the desired device
191 * This walks the bus device list and returns a pointer to the interface
192 * with the matching minor and driver. Note, this only works for devices
193 * that share the USB major number.
195 struct usb_interface
*usb_find_interface(struct usb_driver
*drv
, int minor
)
197 struct find_interface_arg argb
;
201 argb
.drv
= &drv
->drvwrap
.driver
;
203 dev
= bus_find_device(&usb_bus_type
, NULL
, &argb
, __find_interface
);
205 /* Drop reference count from bus_find_device */
208 return dev
? to_usb_interface(dev
) : NULL
;
210 EXPORT_SYMBOL_GPL(usb_find_interface
);
213 * usb_release_dev - free a usb device structure when all users of it are finished.
214 * @dev: device that's been disconnected
216 * Will be called only by the device core when all users of this usb device are
219 static void usb_release_dev(struct device
*dev
)
221 struct usb_device
*udev
;
224 udev
= to_usb_device(dev
);
225 hcd
= bus_to_hcd(udev
->bus
);
227 usb_destroy_configuration(udev
);
228 usb_release_bos_descriptor(udev
);
230 kfree(udev
->product
);
231 kfree(udev
->manufacturer
);
236 static int usb_dev_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
238 struct usb_device
*usb_dev
;
240 usb_dev
= to_usb_device(dev
);
242 if (add_uevent_var(env
, "BUSNUM=%03d", usb_dev
->bus
->busnum
))
245 if (add_uevent_var(env
, "DEVNUM=%03d", usb_dev
->devnum
))
253 /* USB device Power-Management thunks.
254 * There's no need to distinguish here between quiescing a USB device
255 * and powering it down; the generic_suspend() routine takes care of
256 * it by skipping the usb_port_suspend() call for a quiesce. And for
257 * USB interfaces there's no difference at all.
260 static int usb_dev_prepare(struct device
*dev
)
262 return 0; /* Implement eventually? */
265 static void usb_dev_complete(struct device
*dev
)
267 /* Currently used only for rebinding interfaces */
268 usb_resume_complete(dev
);
271 static int usb_dev_suspend(struct device
*dev
)
273 return usb_suspend(dev
, PMSG_SUSPEND
);
276 static int usb_dev_resume(struct device
*dev
)
278 return usb_resume(dev
, PMSG_RESUME
);
281 static int usb_dev_freeze(struct device
*dev
)
283 return usb_suspend(dev
, PMSG_FREEZE
);
286 static int usb_dev_thaw(struct device
*dev
)
288 return usb_resume(dev
, PMSG_THAW
);
291 static int usb_dev_poweroff(struct device
*dev
)
293 return usb_suspend(dev
, PMSG_HIBERNATE
);
296 static int usb_dev_restore(struct device
*dev
)
298 return usb_resume(dev
, PMSG_RESTORE
);
301 static const struct dev_pm_ops usb_device_pm_ops
= {
302 .prepare
= usb_dev_prepare
,
303 .complete
= usb_dev_complete
,
304 .suspend
= usb_dev_suspend
,
305 .resume
= usb_dev_resume
,
306 .freeze
= usb_dev_freeze
,
307 .thaw
= usb_dev_thaw
,
308 .poweroff
= usb_dev_poweroff
,
309 .restore
= usb_dev_restore
,
310 #ifdef CONFIG_USB_SUSPEND
311 .runtime_suspend
= usb_runtime_suspend
,
312 .runtime_resume
= usb_runtime_resume
,
313 .runtime_idle
= usb_runtime_idle
,
317 #endif /* CONFIG_PM */
320 static char *usb_devnode(struct device
*dev
,
321 umode_t
*mode
, kuid_t
*uid
, kgid_t
*gid
)
323 struct usb_device
*usb_dev
;
325 usb_dev
= to_usb_device(dev
);
326 return kasprintf(GFP_KERNEL
, "bus/usb/%03d/%03d",
327 usb_dev
->bus
->busnum
, usb_dev
->devnum
);
330 struct device_type usb_device_type
= {
331 .name
= "usb_device",
332 .release
= usb_release_dev
,
333 .uevent
= usb_dev_uevent
,
334 .devnode
= usb_devnode
,
336 .pm
= &usb_device_pm_ops
,
341 /* Returns 1 if @usb_bus is WUSB, 0 otherwise */
342 static unsigned usb_bus_is_wusb(struct usb_bus
*bus
)
344 struct usb_hcd
*hcd
= container_of(bus
, struct usb_hcd
, self
);
345 return hcd
->wireless
;
350 * usb_alloc_dev - usb device constructor (usbcore-internal)
351 * @parent: hub to which device is connected; null to allocate a root hub
352 * @bus: bus used to access the device
353 * @port1: one-based index of port; ignored for root hubs
354 * Context: !in_interrupt()
356 * Only hub drivers (including virtual root hub drivers for host
357 * controllers) should ever call this.
359 * This call may not be used in a non-sleeping context.
361 struct usb_device
*usb_alloc_dev(struct usb_device
*parent
,
362 struct usb_bus
*bus
, unsigned port1
)
364 struct usb_device
*dev
;
365 struct usb_hcd
*usb_hcd
= bus_to_hcd(bus
);
366 unsigned root_hub
= 0;
368 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
372 if (!usb_get_hcd(usb_hcd
)) {
376 /* Root hubs aren't true devices, so don't allocate HCD resources */
377 if (usb_hcd
->driver
->alloc_dev
&& parent
&&
378 !usb_hcd
->driver
->alloc_dev(usb_hcd
, dev
)) {
379 usb_put_hcd(bus_to_hcd(bus
));
384 device_initialize(&dev
->dev
);
385 dev
->dev
.bus
= &usb_bus_type
;
386 dev
->dev
.type
= &usb_device_type
;
387 dev
->dev
.groups
= usb_device_groups
;
388 dev
->dev
.dma_mask
= bus
->controller
->dma_mask
;
389 set_dev_node(&dev
->dev
, dev_to_node(bus
->controller
));
390 dev
->state
= USB_STATE_ATTACHED
;
391 dev
->lpm_disable_count
= 1;
392 atomic_set(&dev
->urbnum
, 0);
394 INIT_LIST_HEAD(&dev
->ep0
.urb_list
);
395 dev
->ep0
.desc
.bLength
= USB_DT_ENDPOINT_SIZE
;
396 dev
->ep0
.desc
.bDescriptorType
= USB_DT_ENDPOINT
;
397 /* ep0 maxpacket comes later, from device descriptor */
398 usb_enable_endpoint(dev
, &dev
->ep0
, false);
401 /* Save readable and stable topology id, distinguishing devices
402 * by location for diagnostics, tools, driver model, etc. The
403 * string is a path along hub ports, from the root. Each device's
404 * dev->devpath will be stable until USB is re-cabled, and hubs
405 * are often labeled with these port numbers. The name isn't
406 * as stable: bus->busnum changes easily from modprobe order,
407 * cardbus or pci hotplugging, and so on.
409 if (unlikely(!parent
)) {
410 dev
->devpath
[0] = '0';
413 dev
->dev
.parent
= bus
->controller
;
414 dev_set_name(&dev
->dev
, "usb%d", bus
->busnum
);
417 /* match any labeling on the hubs; it's one-based */
418 if (parent
->devpath
[0] == '0') {
419 snprintf(dev
->devpath
, sizeof dev
->devpath
,
421 /* Root ports are not counted in route string */
424 snprintf(dev
->devpath
, sizeof dev
->devpath
,
425 "%s.%d", parent
->devpath
, port1
);
426 /* Route string assumes hubs have less than 16 ports */
428 dev
->route
= parent
->route
+
429 (port1
<< ((parent
->level
- 1)*4));
431 dev
->route
= parent
->route
+
432 (15 << ((parent
->level
- 1)*4));
435 dev
->dev
.parent
= &parent
->dev
;
436 dev_set_name(&dev
->dev
, "%d-%s", bus
->busnum
, dev
->devpath
);
438 /* hub driver sets up TT records */
441 dev
->portnum
= port1
;
443 dev
->parent
= parent
;
444 INIT_LIST_HEAD(&dev
->filelist
);
447 pm_runtime_set_autosuspend_delay(&dev
->dev
,
448 usb_autosuspend_delay
* 1000);
449 dev
->connect_time
= jiffies
;
450 dev
->active_duration
= -jiffies
;
452 if (root_hub
) /* Root hub always ok [and always wired] */
455 dev
->authorized
= usb_hcd
->authorized_default
;
456 dev
->wusb
= usb_bus_is_wusb(bus
)? 1 : 0;
462 * usb_get_dev - increments the reference count of the usb device structure
463 * @dev: the device being referenced
465 * Each live reference to a device should be refcounted.
467 * Drivers for USB interfaces should normally record such references in
468 * their probe() methods, when they bind to an interface, and release
469 * them by calling usb_put_dev(), in their disconnect() methods.
471 * A pointer to the device with the incremented reference counter is returned.
473 struct usb_device
*usb_get_dev(struct usb_device
*dev
)
476 get_device(&dev
->dev
);
479 EXPORT_SYMBOL_GPL(usb_get_dev
);
482 * usb_put_dev - release a use of the usb device structure
483 * @dev: device that's been disconnected
485 * Must be called when a user of a device is finished with it. When the last
486 * user of the device calls this function, the memory of the device is freed.
488 void usb_put_dev(struct usb_device
*dev
)
491 put_device(&dev
->dev
);
493 EXPORT_SYMBOL_GPL(usb_put_dev
);
496 * usb_get_intf - increments the reference count of the usb interface structure
497 * @intf: the interface being referenced
499 * Each live reference to a interface must be refcounted.
501 * Drivers for USB interfaces should normally record such references in
502 * their probe() methods, when they bind to an interface, and release
503 * them by calling usb_put_intf(), in their disconnect() methods.
505 * A pointer to the interface with the incremented reference counter is
508 struct usb_interface
*usb_get_intf(struct usb_interface
*intf
)
511 get_device(&intf
->dev
);
514 EXPORT_SYMBOL_GPL(usb_get_intf
);
517 * usb_put_intf - release a use of the usb interface structure
518 * @intf: interface that's been decremented
520 * Must be called when a user of an interface is finished with it. When the
521 * last user of the interface calls this function, the memory of the interface
524 void usb_put_intf(struct usb_interface
*intf
)
527 put_device(&intf
->dev
);
529 EXPORT_SYMBOL_GPL(usb_put_intf
);
531 /* USB device locking
533 * USB devices and interfaces are locked using the semaphore in their
534 * embedded struct device. The hub driver guarantees that whenever a
535 * device is connected or disconnected, drivers are called with the
536 * USB device locked as well as their particular interface.
538 * Complications arise when several devices are to be locked at the same
539 * time. Only hub-aware drivers that are part of usbcore ever have to
540 * do this; nobody else needs to worry about it. The rule for locking
543 * When locking both a device and its parent, always lock the
548 * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure
549 * @udev: device that's being locked
550 * @iface: interface bound to the driver making the request (optional)
552 * Attempts to acquire the device lock, but fails if the device is
553 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
554 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
555 * lock, the routine polls repeatedly. This is to prevent deadlock with
556 * disconnect; in some drivers (such as usb-storage) the disconnect()
557 * or suspend() method will block waiting for a device reset to complete.
559 * Returns a negative error code for failure, otherwise 0.
561 int usb_lock_device_for_reset(struct usb_device
*udev
,
562 const struct usb_interface
*iface
)
564 unsigned long jiffies_expire
= jiffies
+ HZ
;
566 if (udev
->state
== USB_STATE_NOTATTACHED
)
568 if (udev
->state
== USB_STATE_SUSPENDED
)
569 return -EHOSTUNREACH
;
570 if (iface
&& (iface
->condition
== USB_INTERFACE_UNBINDING
||
571 iface
->condition
== USB_INTERFACE_UNBOUND
))
574 while (!usb_trylock_device(udev
)) {
576 /* If we can't acquire the lock after waiting one second,
577 * we're probably deadlocked */
578 if (time_after(jiffies
, jiffies_expire
))
582 if (udev
->state
== USB_STATE_NOTATTACHED
)
584 if (udev
->state
== USB_STATE_SUSPENDED
)
585 return -EHOSTUNREACH
;
586 if (iface
&& (iface
->condition
== USB_INTERFACE_UNBINDING
||
587 iface
->condition
== USB_INTERFACE_UNBOUND
))
592 EXPORT_SYMBOL_GPL(usb_lock_device_for_reset
);
595 * usb_get_current_frame_number - return current bus frame number
596 * @dev: the device whose bus is being queried
598 * Returns the current frame number for the USB host controller
599 * used with the given USB device. This can be used when scheduling
600 * isochronous requests.
602 * Note that different kinds of host controller have different
603 * "scheduling horizons". While one type might support scheduling only
604 * 32 frames into the future, others could support scheduling up to
605 * 1024 frames into the future.
607 int usb_get_current_frame_number(struct usb_device
*dev
)
609 return usb_hcd_get_frame_number(dev
);
611 EXPORT_SYMBOL_GPL(usb_get_current_frame_number
);
613 /*-------------------------------------------------------------------*/
615 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
616 * extra field of the interface and endpoint descriptor structs.
619 int __usb_get_extra_descriptor(char *buffer
, unsigned size
,
620 unsigned char type
, void **ptr
)
622 struct usb_descriptor_header
*header
;
624 while (size
>= sizeof(struct usb_descriptor_header
)) {
625 header
= (struct usb_descriptor_header
*)buffer
;
627 if (header
->bLength
< 2) {
629 "%s: bogus descriptor, type %d length %d\n",
631 header
->bDescriptorType
,
636 if (header
->bDescriptorType
== type
) {
641 buffer
+= header
->bLength
;
642 size
-= header
->bLength
;
646 EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor
);
649 * usb_alloc_coherent - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
650 * @dev: device the buffer will be used with
651 * @size: requested buffer size
652 * @mem_flags: affect whether allocation may block
653 * @dma: used to return DMA address of buffer
655 * Return value is either null (indicating no buffer could be allocated), or
656 * the cpu-space pointer to a buffer that may be used to perform DMA to the
657 * specified device. Such cpu-space buffers are returned along with the DMA
658 * address (through the pointer provided).
660 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
661 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
662 * hardware during URB completion/resubmit. The implementation varies between
663 * platforms, depending on details of how DMA will work to this device.
664 * Using these buffers also eliminates cacheline sharing problems on
665 * architectures where CPU caches are not DMA-coherent. On systems without
666 * bus-snooping caches, these buffers are uncached.
668 * When the buffer is no longer used, free it with usb_free_coherent().
670 void *usb_alloc_coherent(struct usb_device
*dev
, size_t size
, gfp_t mem_flags
,
673 if (!dev
|| !dev
->bus
)
675 return hcd_buffer_alloc(dev
->bus
, size
, mem_flags
, dma
);
677 EXPORT_SYMBOL_GPL(usb_alloc_coherent
);
680 * usb_free_coherent - free memory allocated with usb_alloc_coherent()
681 * @dev: device the buffer was used with
682 * @size: requested buffer size
683 * @addr: CPU address of buffer
684 * @dma: DMA address of buffer
686 * This reclaims an I/O buffer, letting it be reused. The memory must have
687 * been allocated using usb_alloc_coherent(), and the parameters must match
688 * those provided in that allocation request.
690 void usb_free_coherent(struct usb_device
*dev
, size_t size
, void *addr
,
693 if (!dev
|| !dev
->bus
)
697 hcd_buffer_free(dev
->bus
, size
, addr
, dma
);
699 EXPORT_SYMBOL_GPL(usb_free_coherent
);
702 * usb_buffer_map - create DMA mapping(s) for an urb
703 * @urb: urb whose transfer_buffer/setup_packet will be mapped
705 * Return value is either null (indicating no buffer could be mapped), or
706 * the parameter. URB_NO_TRANSFER_DMA_MAP is
707 * added to urb->transfer_flags if the operation succeeds. If the device
708 * is connected to this system through a non-DMA controller, this operation
711 * This call would normally be used for an urb which is reused, perhaps
712 * as the target of a large periodic transfer, with usb_buffer_dmasync()
713 * calls to synchronize memory and dma state.
715 * Reverse the effect of this call with usb_buffer_unmap().
718 struct urb
*usb_buffer_map(struct urb
*urb
)
721 struct device
*controller
;
725 || !(bus
= urb
->dev
->bus
)
726 || !(controller
= bus
->controller
))
729 if (controller
->dma_mask
) {
730 urb
->transfer_dma
= dma_map_single(controller
,
731 urb
->transfer_buffer
, urb
->transfer_buffer_length
,
732 usb_pipein(urb
->pipe
)
733 ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
734 /* FIXME generic api broken like pci, can't report errors */
735 /* if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; */
737 urb
->transfer_dma
= ~0;
738 urb
->transfer_flags
|= URB_NO_TRANSFER_DMA_MAP
;
741 EXPORT_SYMBOL_GPL(usb_buffer_map
);
744 /* XXX DISABLED, no users currently. If you wish to re-enable this
745 * XXX please determine whether the sync is to transfer ownership of
746 * XXX the buffer from device to cpu or vice verse, and thusly use the
747 * XXX appropriate _for_{cpu,device}() method. -DaveM
752 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
753 * @urb: urb whose transfer_buffer/setup_packet will be synchronized
755 void usb_buffer_dmasync(struct urb
*urb
)
758 struct device
*controller
;
761 || !(urb
->transfer_flags
& URB_NO_TRANSFER_DMA_MAP
)
763 || !(bus
= urb
->dev
->bus
)
764 || !(controller
= bus
->controller
))
767 if (controller
->dma_mask
) {
768 dma_sync_single_for_cpu(controller
,
769 urb
->transfer_dma
, urb
->transfer_buffer_length
,
770 usb_pipein(urb
->pipe
)
771 ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
772 if (usb_pipecontrol(urb
->pipe
))
773 dma_sync_single_for_cpu(controller
,
775 sizeof(struct usb_ctrlrequest
),
779 EXPORT_SYMBOL_GPL(usb_buffer_dmasync
);
783 * usb_buffer_unmap - free DMA mapping(s) for an urb
784 * @urb: urb whose transfer_buffer will be unmapped
786 * Reverses the effect of usb_buffer_map().
789 void usb_buffer_unmap(struct urb
*urb
)
792 struct device
*controller
;
795 || !(urb
->transfer_flags
& URB_NO_TRANSFER_DMA_MAP
)
797 || !(bus
= urb
->dev
->bus
)
798 || !(controller
= bus
->controller
))
801 if (controller
->dma_mask
) {
802 dma_unmap_single(controller
,
803 urb
->transfer_dma
, urb
->transfer_buffer_length
,
804 usb_pipein(urb
->pipe
)
805 ? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
807 urb
->transfer_flags
&= ~URB_NO_TRANSFER_DMA_MAP
;
809 EXPORT_SYMBOL_GPL(usb_buffer_unmap
);
814 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
815 * @dev: device to which the scatterlist will be mapped
816 * @is_in: mapping transfer direction
817 * @sg: the scatterlist to map
818 * @nents: the number of entries in the scatterlist
820 * Return value is either < 0 (indicating no buffers could be mapped), or
821 * the number of DMA mapping array entries in the scatterlist.
823 * The caller is responsible for placing the resulting DMA addresses from
824 * the scatterlist into URB transfer buffer pointers, and for setting the
825 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs.
827 * Top I/O rates come from queuing URBs, instead of waiting for each one
828 * to complete before starting the next I/O. This is particularly easy
829 * to do with scatterlists. Just allocate and submit one URB for each DMA
830 * mapping entry returned, stopping on the first error or when all succeed.
831 * Better yet, use the usb_sg_*() calls, which do that (and more) for you.
833 * This call would normally be used when translating scatterlist requests,
834 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
835 * may be able to coalesce mappings for improved I/O efficiency.
837 * Reverse the effect of this call with usb_buffer_unmap_sg().
839 int usb_buffer_map_sg(const struct usb_device
*dev
, int is_in
,
840 struct scatterlist
*sg
, int nents
)
843 struct device
*controller
;
847 || !(controller
= bus
->controller
)
848 || !controller
->dma_mask
)
851 /* FIXME generic api broken like pci, can't report errors */
852 return dma_map_sg(controller
, sg
, nents
,
853 is_in
? DMA_FROM_DEVICE
: DMA_TO_DEVICE
) ? : -ENOMEM
;
855 EXPORT_SYMBOL_GPL(usb_buffer_map_sg
);
858 /* XXX DISABLED, no users currently. If you wish to re-enable this
859 * XXX please determine whether the sync is to transfer ownership of
860 * XXX the buffer from device to cpu or vice verse, and thusly use the
861 * XXX appropriate _for_{cpu,device}() method. -DaveM
866 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
867 * @dev: device to which the scatterlist will be mapped
868 * @is_in: mapping transfer direction
869 * @sg: the scatterlist to synchronize
870 * @n_hw_ents: the positive return value from usb_buffer_map_sg
872 * Use this when you are re-using a scatterlist's data buffers for
873 * another USB request.
875 void usb_buffer_dmasync_sg(const struct usb_device
*dev
, int is_in
,
876 struct scatterlist
*sg
, int n_hw_ents
)
879 struct device
*controller
;
883 || !(controller
= bus
->controller
)
884 || !controller
->dma_mask
)
887 dma_sync_sg_for_cpu(controller
, sg
, n_hw_ents
,
888 is_in
? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
890 EXPORT_SYMBOL_GPL(usb_buffer_dmasync_sg
);
895 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
896 * @dev: device to which the scatterlist will be mapped
897 * @is_in: mapping transfer direction
898 * @sg: the scatterlist to unmap
899 * @n_hw_ents: the positive return value from usb_buffer_map_sg
901 * Reverses the effect of usb_buffer_map_sg().
903 void usb_buffer_unmap_sg(const struct usb_device
*dev
, int is_in
,
904 struct scatterlist
*sg
, int n_hw_ents
)
907 struct device
*controller
;
911 || !(controller
= bus
->controller
)
912 || !controller
->dma_mask
)
915 dma_unmap_sg(controller
, sg
, n_hw_ents
,
916 is_in
? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
918 EXPORT_SYMBOL_GPL(usb_buffer_unmap_sg
);
921 /* To disable USB, kernel command line is 'nousb' not 'usbcore.nousb' */
923 module_param(nousb
, bool, 0444);
925 core_param(nousb
, nousb
, bool, 0444);
929 * for external read access to <nousb>
931 int usb_disabled(void)
935 EXPORT_SYMBOL_GPL(usb_disabled
);
938 * Notifications of device and interface registration
940 static int usb_bus_notify(struct notifier_block
*nb
, unsigned long action
,
943 struct device
*dev
= data
;
946 case BUS_NOTIFY_ADD_DEVICE
:
947 if (dev
->type
== &usb_device_type
)
948 (void) usb_create_sysfs_dev_files(to_usb_device(dev
));
949 else if (dev
->type
== &usb_if_device_type
)
950 usb_create_sysfs_intf_files(to_usb_interface(dev
));
953 case BUS_NOTIFY_DEL_DEVICE
:
954 if (dev
->type
== &usb_device_type
)
955 usb_remove_sysfs_dev_files(to_usb_device(dev
));
956 else if (dev
->type
== &usb_if_device_type
)
957 usb_remove_sysfs_intf_files(to_usb_interface(dev
));
963 static struct notifier_block usb_bus_nb
= {
964 .notifier_call
= usb_bus_notify
,
967 struct dentry
*usb_debug_root
;
968 EXPORT_SYMBOL_GPL(usb_debug_root
);
970 static struct dentry
*usb_debug_devices
;
972 static int usb_debugfs_init(void)
974 usb_debug_root
= debugfs_create_dir("usb", NULL
);
978 usb_debug_devices
= debugfs_create_file("devices", 0444,
979 usb_debug_root
, NULL
,
980 &usbfs_devices_fops
);
981 if (!usb_debug_devices
) {
982 debugfs_remove(usb_debug_root
);
983 usb_debug_root
= NULL
;
990 static void usb_debugfs_cleanup(void)
992 debugfs_remove(usb_debug_devices
);
993 debugfs_remove(usb_debug_root
);
999 static int __init
usb_init(void)
1003 pr_info("%s: USB support disabled\n", usbcore_name
);
1007 retval
= usb_debugfs_init();
1011 usb_acpi_register();
1012 retval
= bus_register(&usb_bus_type
);
1014 goto bus_register_failed
;
1015 retval
= bus_register_notifier(&usb_bus_type
, &usb_bus_nb
);
1017 goto bus_notifier_failed
;
1018 retval
= usb_major_init();
1020 goto major_init_failed
;
1021 retval
= usb_register(&usbfs_driver
);
1023 goto driver_register_failed
;
1024 retval
= usb_devio_init();
1026 goto usb_devio_init_failed
;
1027 retval
= usb_hub_init();
1029 goto hub_init_failed
;
1030 retval
= usb_register_device_driver(&usb_generic_driver
, THIS_MODULE
);
1036 usb_devio_cleanup();
1037 usb_devio_init_failed
:
1038 usb_deregister(&usbfs_driver
);
1039 driver_register_failed
:
1040 usb_major_cleanup();
1042 bus_unregister_notifier(&usb_bus_type
, &usb_bus_nb
);
1043 bus_notifier_failed
:
1044 bus_unregister(&usb_bus_type
);
1045 bus_register_failed
:
1046 usb_acpi_unregister();
1047 usb_debugfs_cleanup();
1055 static void __exit
usb_exit(void)
1057 /* This will matter if shutdown/reboot does exitcalls. */
1061 usb_deregister_device_driver(&usb_generic_driver
);
1062 usb_major_cleanup();
1063 usb_deregister(&usbfs_driver
);
1064 usb_devio_cleanup();
1066 bus_unregister_notifier(&usb_bus_type
, &usb_bus_nb
);
1067 bus_unregister(&usb_bus_type
);
1068 usb_acpi_unregister();
1069 usb_debugfs_cleanup();
1072 subsys_initcall(usb_init
);
1073 module_exit(usb_exit
);
1074 MODULE_LICENSE("GPL");